#include <iostream>
#include <string>
#include <vector>
#include <map>

using namespace std;

#define INF 		2000000007
#define MOD			1000000007

#define MAX 		1000005

#define REP(i,n)	for(int i=0;i<(n);++i)
#define REPS(i,s,t)	for(int i=(s);i<(t);++i)

typedef unsigned long long int ull;

int main(){
	int N;cin >> N;

	unsigned int dp[MAX];

	dp[0]=dp[1]=0;
	dp[2]=dp[3]=1;
	REPS(i,4,N+1){
		dp[i] = (dp[i-2]+dp[i-3])%MOD;
	}
	if(N==1)cout << "1\n";
	else if(N==2)cout << "2\n";
	else cout << (dp[N] + dp[N-1] + dp[N-2])%MOD << endl;
}